Pumps for admixing solid or semi-solid ingredients to a viscous fluid under pressure



July 12, 1966 H. GRA 3,260,210

PUMPS ADMIXING SOLID OR E I-SOLID INGREDIENTS 0 A VISCOUS FLUID UNDER PRESSURE Filed Nov. 12, 1965 2 Sheets-Sheet 1 V fizr /4 l I l INVENTOR. BY //W M71, 44 fl July 12, 1966 H. GRAM 3,260,210

PUMPS FOR ADMIXING SOLID OR SEMI-SOLID INGREDIENTS TO A VISCOUS FLUID UNDER PRESSURE Filed Nov. 12, 1963 2 Sheets-Sheet 2 I NVENTOR.

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United States Patent 3,260,210 PUMPS FOR ADMIXING SOLID 0R SEMI-SOLID INGREDIENTS TO A VISCOUS FLUID UNDER PRESSURE Hans Gram, Vojens, Denmark, assignor to Brodrene Gram A/S, Vojens, Denmark Filed Nov. 12, 1963, Ser. No. 322,640 Claims priority, application Denmark, Nov. 16, 1962,

3 Claims. c1. 103-2 This invention relates to a pump for admixing solid or semi-solid ingredients to a viscous fluid under pressure, e.g. for admixing caramel, nougat, nuts or fruits toice cream.

It is known to construct pumps for this purpose in the general form of a vane pump, a supply for the solid or semi-solid material being connected to the low pressure side of the pump, and both an'inlet and an outlet for the pressurized fluid being connected to the high pressure side of the pump.

It is an object of the invention to construct a pump of the type referred to in such a manner as to obtain a particularly accurate and reliable guiding of the vanes by structurally simple means, in spite of the fact that such pumps frequently have to handle material of a rather sticky nature.

According to the invention, a pump for admixing solid or semi-solid ingredients to a viscous fluid under pressure comprises a pumping chamber having a first inner wall portion shaped as part of a cylindrical surface, a second inner wall portion likewise shaped as part of a cylindrical surface co-axial with but angularly displaced .from said first inner wall portion and having a smaller radius of curvature than the latter, an inlet opening for said solid or semi-solid ingredients between said first and second inner wall portions, inlet and outlet openings for said pressurized fluid in a zone of said pumping chamber remote from said inlet opening for solid or semi-solid ingredients, a rotor mounted for rotation in said pumping chamber about an axis coinciding with that of said first and second inner wall portions, said rotor being shaped as a cylindrical body having substantially the same wall portions, each vane being constructed with an inwardly facing shoulder for engagement with said cam, the distance between said shoulder of each vane and the end face thereof being equal in the radial distance between said cam and said first inner wall portion, each pair of vanes being interconnected to form a blade having a U-shaped marginal recess, the length of which is equal to the sum of the thickness of one blade plus the radial distance between said first portion of the inner wall of said pumping chamber and the cylindrical surface of said rotor.

In a pump constructed as described, each vane, immediately before arriving at said first inner wall portion, will be caused by the engagement of said shoulder with said cam to be projected from the cylindrical surface of the rotor exactly enough to engage said inner wall portion, the mutual engagement of the U-shaped marginal recesses of the two blades limiting the said movement of projection of the vanes to the exact value required, thus preventing excessive projection of the vanes due to influences other than that of said cam, e.g. the pressure prevailing in the pump.

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The invention will now be described in further detail with reference to the accompanying drawings, in which- FIG. 1 shows a diametrical section through one form of a pump according to the invention, and

FIG. 2 an axial section along the line II-II in FIG. 1.

In the drawing, 1 is the housing of the pump, and 2 a cover of said housing. A bearing 3 is attached to one side face of the housing 1 by welding. In the bearing 3 a lining 4 is mounted which serves for rotatably supporting a shaft 5 which is constructed with coupling projections 6. Integrally with the shaft 5 there is formed a rotor consisting of a plate 7 which along its circumference carries four laterally extending ring segments 8 forming a cylindrical body with two diametrical slots at right angles to one another. Two blades or pairs of vanes 9 and 10, each of a length exceeding the diameter of said cylindrical body, are slidably mounted in the diametrical slots thereof.

In operation of the pump, the rotor 7 is driven in the direction marked by an arrow 11, and the parts of the vanes 9 and 10 projecting from the rotor 7 move in a space 12 between the cylindrical surface of the rotor 7 and a first portion 13 of the inner wall of the pumping chamber, which portion follows an inlet opening for solid or semi-solid ingredients, as viewed in the direction of rotation of the rotor. The space 12 has a constant radial width, the portion 13 of the inner wall of the pumping chamber being constructed as a circular cylindrical surface co-axial with the rotor 7.

Diametrically opposite the said first portion 13 of the inner wall of the pumping chamber, a second inner wall portion 15 is provided which is likewise shaped as a cylinder co-axial with the rotor 7, but has approximately the same radius of curvature as the cylindrical surface of the rotor 7 so that the latter engages said second inner wall portion at a sliding fit. In the embodiment shown, the inner wall portion 15 is constituted by a cylindrical element 16 having the same thickness as the radial width of the space 12, and being attached to the pump housing 1 by means of screws 17. The employment of such a separate element 16 of the said thickness has the advantage that the inner wall of the pump housing 1 in the zone of the element 16 will have the same radius of curvature as in the zone of the inner wall portion 13 so that the intern-a1 shape of the housing 1 becomes very simple. If it is not desired to make use of this simplification, the element 16 may be constituted by an integral portion of the pump housing.

In the embodiment illustrated, the pump is intended for admixing ingredients e.g. consisting of caramel, nougat, nuts or fruits to ice cream which is supplied from a continuous ice cream freezer, not shown. To this end the pump is constructed with two connecting pipe stubs 18 and 19 of which the stub 18 is connected with the continuous freezer While the stub 19 forms an outlet through which the ice cream leaves the pump after the ingredients supplied through the low pressure inlet opening 14 have been added thereto. Since the ice cream supplied through the stub 18 is under pressure and the other ingredients admitted for mixing therewith through the inlet opening 14 are at little or no pressure, it will be seen that in the case considered, the pump also serves as a pressure maintaining pump.

The material conveyed by the pump may have a tendency to adhere to the rotor 7 and the vanes 9 and 10, thus causing these to adhere to the ring segments 8. In order to obtain a controlled guiding of the vanes before hese enter into the space 12, a curved guiding cam is provided on the inner side of the cover 2 in the formof a rotatably mounted roller 20, and moreover each vane 9, 10 has an inwardly facing marginal shoulder 21 located at a distance from the end face of the vane considered, equal to the shortest distance between the inner wall portion 13 and the circumference of the roller 20. Thus, when the rotor 7 is rotated in the direction of the arrow 11, the co-operation of the shoulder 21 of each vane with the circumference of the roller 20 will cause the vane to be projected from the circumferential surface of the rotor 7 through a distance corresponding to the radial width of the space 12, if such projection has not already taken place under the influence of the pressure prevailing at the pressure side of the pump, which pressure has a tendency to displace the vanes in a direction upwards, i.e. towards the inlet opening 14.

In order to prevent excessive projection of the vanes, e.g. under the influence of the pressure difference between the suction and pressure sides of the pump, the blades are constructed at the edges thereof facing one another, with marginal recesses 22, FIG. 1, and 23, FIG. 2, respectively. The length of each of these marginal recesses is equal to the sum of the thickness of one blade and the radial width of the space 12, so that each of the marginal recesses only permits the blade in question to be projected just enough to cover the space 12.

In order to avoid abrupt movements of the vanes, the element 16 is constructed with an inclined entrance portion 24, FIG. 1, and another inclined portion 25, in the position where the vanes leave the elements 16.

The end faces of the vanes 9 and 10 may be constructed as cylindrical surfaces having the same radius of curvature as the inner wall portion 13, whereby a good sealing contact is obtained between the wanes and the said inner wall portion. In that case, the end faces of the vanes will have line contact with the elements 16 but since the circumferential surface of the rotor 7 is in sliding contact with the element 16, a good sealing contact is also obtained in this zone.

What I claim is:

l. A pump for admixing solid or semi-solid ingredients to a viscous fluid under pressure, said pump comprising a pumping chamber having a first inner wall portion shaped as part of a cylindrical surface, a second inner wall portion likewise shaped as part of a cylindrical surface co-axial with, but angularly displaced from said first inner wall portion at the end thereof adjacent said low pressure inlet opening and having a smaller radius of curvature than the latter, a low pressure inlet opening for said solid or semi-solid ingredients between said first and second inner wall portions, said inlet opening having two spaced flat parallel side walls facing each other and extending perpendicularly to an axis coinciding with that of said first and second inner wall portions, inlet and outlet openings for said pressurized fluid in a zone of said pumping chamber remote from said low pressure opening for solid or semi-solid ingredients, a rotor mounted for rotation in said pumping chamber about said axis, said rotor being shaped as a cylindrical body having substantially the same radius of curvature as said second inner wall portion, the direction of rotation of said rotor being from said second inner wall portion vi-a said inlet opening for solid or semi-solid ingredients to said first inner wall portion, two pairs of vanes being freely slidably mounted in mutually perpendicular diametrical slots of said rotor, the width of said vanes being equal to the spacing of said fiat-parallel side walls, a curved cam being mounted in said pumping chamber in an eccentric posi-.

tion with respect to said first and second inner wall portions, each vane being constructed with an inwardly facing shoulder for engagement with said cam, the distance between said shoulder of each vane and the end face thereof being equal to the radial distance between said cam and said first inner wall portion, each pair of vanes being interconnected to form a blade having a U-shaped marginal recess, the length of which is equal to the sum of the thickness of one blade plus the radial distance between said first portion of the inner wall of said pumping chamber and the cylindrical surface of said rotor.

2. A pump as in claim 1, in which said cam consists of a roller rotatably mounted on one end wall of said pumping chamber and accommodated in a recess of said rotor.

3. A pump for intermixing solid or semi solid ingredients with a viscous fluid under pressure, comprising a pumping chamber having a first inner wall portion shaped as part of a cylindrical surface, a second inner wall portion likewise shaped as part of a cylindrical surface coaxial with, but angularly displaced from, said first inner wall portion and having a smaller radius of curvature than the first inner wall portion, said chamber being formed with a low pressure inlet opening for said ingredients between said first and second inner wall portions, and with inlet and outlet openings for said pressurized fluid, said last-mentioned openings both being in a zone of said pumping chamber generally diametrically opposed to said low pressure inlet opening, a rotor mounted for rotation in said pumping chamber about an axis coinciding with that of said first and second inner wall portions, said rotor being shaped as a cylindrical body having substantially the same radius of curvature as said second inner wall portion and being disposed for rotation across said low pressure inlet opening in a direction from said second inner wall portion toward said first inner wall portion, two pairs of vanes disposed for sliding movement through said rotor in diametrical planes thereof normal to each other, the vanes of each said pair being fixedly interconnected across the rotational axis of the rotor for limited diametrical movement as a unit relative to the rotor and to the other said pair of vanes, the vanes of one said pair normally engaging said first and second inner wall portions respectively to isolate said inlet opening for pressurized fluid from said low pressure inlet opening, while the vanes of said other pair are free for diametrical movement into said low pressure inlet opening in response to differences in the pressures acting upon the respective vanes of said other pair, and for angular movement with the rotor across said low pressure inlet opening.

References Cited by the Examiner UNlTED STATES PATENTS 1,697,924 l/1929 Lusso 103136 1,833,275 11/1931 Burrneister lO3-7 2,473,309 6/1949 Stephens 103-136 2,754,766 7/1956 Feroy 103136 2,819,677 1/1958 Leath 103-136 3,132,847 5/1964 Mercuriali 103-7 MARK NEWMAN, Primary Examiner.

W. J. KRAUSS, Assistant Examiner. 

1. A PUMP FOR ADMIXING SOLID OR SEMI-SOLID INGREDIENTS TO A VISCOUS FLUID UNDER PRESSURE, SAID PUMP COMPRISING A PUMPING CHAMBER HAVING A FIRST INNER WALL PORTION SHAPED AS PART OF A CYLINDRICAL SURFACE, A SECOND INNER WALL PORTION LIKEWISE SHAPED AS PART OF CYLINDRICAL SURFACE CO-AXIAL WITH, BUT ANGULARLY DISPLACED FROM SAID FIRST INNER WALL PORTION AT THE END THEREOF ADJACENT SAID LOW PRESSURE INLET HAVING AND OPENING A SMALLER RADIUS OF CURVATURE THAN THE LATTER, A LOW PRESSURE INLET OPENING FOR SAID SOLID OR SEMI-SOLID INGREDIENTS BETWEEN SAID FIRST AND SECOND INNER WALL PORTIONS, SAID INLET OPENING HAVING TWO SPACED FLAT PARALLEL SIDE WALLS FACING EACH OTHER AND EXTENDING PERPENDICULARLY TO AN AXIS COINCIDING WITH THAT OF SAID FIRST AND SECOND INNER PORTIONS, INLET AND OUTLET OPENINGS FOR SAID PRESSURIZED FLUID IN A ZONE OF SAID PUMPING CHAMBER REMOTE FROM SAID LOW PRESSURE OPENING FOR SOLID OR SEMI-SOLID INGREDIENTS, OR ROTOR MOUNTED FOR ROTATION IN SAID PUMPING CHAMBER ABOUT SAID AXIS, SAID ROTOR BEING SHAPED AS A CYLINDRICAL BODY HAVING SUBSTANTIALLY THE SAME RADIUS OF CURVATURE AS SAID SECOND INNER WALL PORTION, THE DIRECTION OF ROTATION OF SAID ROTOR BEING FROM SAID SECOND INNER WALL PORTION VIA SAID INLET OPENING FOR SOLID OR SEMI-SOLID INGREDIENTS TO SAID FIRST INNER WALL PORTION, TWO PAIRS OF VANES BEING FREELY SLIDABLY MOUNTED IN MUTUALLY PERPENDICULAR DIAMETRICAL SLOTS OF SAID ROTOR, THE WIDTH OF SAID VANES BEING EQUAL TO THE SPACING OF SAID FLAT PARALLEL SIDE WALLS, A CURVED CAM BEING 